U.S. President Donald Trump has sacked his national security adviser John Bolton.

In a series of Tweets Tuesday afternoon, Trump said the pair had had numerous differences of opinion, and that it was time to end the relationship. Trump also suggested Bolton, known for his hawkish views, had also had disagreements with others in the administration.

Trump said he will name a new person to the role next week, with deputy national security adviser Charles Kupperman taking over in the meantime.

Bolton was long known to have pushed Trump to be harder on North Korea, Russia and Afghanistan, and was a central player in his more hostile dealings with Iran. In fact, the president is sometimes said to have joked about Bolton: “John has never seen a war he doesn’t like.”

Among the issues said to have divided the pair were Trump’s courting of North Korean dictator Kim Jong Un, and his more recent indications that he would be open to meeting Iranian leader Hassan Rouhani.

I informed John Bolton last night that his services are no longer needed at the White House. I disagreed strongly with many of his suggestions, as did others in the Administration, and therefore….

“I informed John Bolton last night that his services are no longer needed at the White House,” Trump tweeted Tuesday.

“I disagreed strongly with many of his suggestions, as did others in the Administration, and therefore … I asked John for his resignation, which was given to me this morning. I thank John very much for his service. I will be naming a new National Security Advisor next week.”

For his part, Bolton almost immediately lashed Trump’s move on Twitter, throwing doubt on the series of events that led to his departure. Trump’s take was that he told Bolton last night that he was no longer needed, and Bolton then gave his resignation this morning. Bolton, however, had a very different recollection.

I offered to resign last night and President Trump said, "Let's talk about it tomorrow."

“I offered to resign last night,” he tweeted, “and President Trump said, ‘Let’s talk about it tomorrow’”

Bolton later told the New York Times by text message that the move had been his, not Trump’s.

“Offered last night without his asking. Slept on it and gave it to him this morning,” he said.

Bolton served as Trump’s third national security adviser. He had been in the job since April 2018, after replacing H.R. McMaster. McMaster had replaced Michael Flynn, who is set to be sentenced by the end of the year for lying to the FBI over contacts with Russian officials.

The firing comes amid a breakdown in peace talks with the Taliban in Afghanistan. The New York Times reports that Bolton spent a great deal of time trying to persuade Trump to call off the deal, which is ultimately what came to pass. In a bizarre announcement by Trump at the weekend, the president said he had set up secret talks with the Taliban at Camp David, but was cancelling them because the Taliban had acted in bad faith. The talks are now “dead,” Trump has said.

But the Times reported that Trump aides were enraged when news stories reported that Bolton had been against the deal, because this ran contrary to Trump’s interests. Similarly Mike Pence, Trump’s vice president, was angered over reports that he, too, had been against the Camp David meeting. The reports were seen as the Bolton team pushing a narrative that Bolton had not been the only one to oppose the Taliban meeting, the Times reported.

I just asked WH press secretary Stephanie Grisham if the Taliban invitation was the breaking point in the Trump-Bolton relationship. She said “no- it was many, many issues.”

As the news of Bolton’s departure broke, Eamon Javers of CNBC tweeted that he had asked Stephanie Grisham, White House press secretary, if the Camp David invite had been the issue that critically divided the pair. She said no, that it came down to “many, many issues.”

However, CNN’s Kaitlan Collins reported that sources told her Bolton and Trump had had a bad argument about the Taliban on Monday night.

John Bolton and President Trump got into a bitter argument last night over the president’s plan to host Taliban leaders at Camp David, two people tell me.

“His opposition to the diplomatic effort in Afghanistan has irritated President Trump, these officials said, and led aides to leave the National Security Council out of sensitive discussions about the agreement,” the Post reported in August.

A source close to Bolton just said this: “Since Ambassador Bolton has been National Security advisor over the last 17 months, there have been no bad deals.”

“The sidelining of Bolton has raised questions about his influence in an administration that is seeking a troop withdrawal from Afghanistan, as well as an ambitious nuclear deal with North Korea and potential engagement with Iranian President Hassan Rouhani. Bolton, U.S. officials said, stands in opposition to those efforts, but he does so increasingly from the periphery.”

Bolton’s abrupt firing Tuesday reportedly came just one hour after he had led a committee meeting on the country’s refugee cap.

Bolton's firing was so sudden that he was leading a principals committee this morning on the refugee cap for next fiscal year, an administration official tells me.The meeting ended just ONE HOUR before Trump tweeted that he had fired Bolton, the official says.

The Washington Post reports that Bolton and Trump loyalist Mike Pompeo, the secretary of state, had been increasingly divided. Bolton, the Post reports, believed Pompeo had political ambitions of his own that were getting in the way of his true role. Pompeo reportedly felt Bolton was too inflexible and hardline on key geopolitical issues.

Citing unnamed administration officials, the Post said Bolton recently indicated he didn’t want to go on TV and defend some of Trump’s positions, especially in relation to Afghanistan and Russia.

According to the New York Times, other recent sources of tension were Trump’s call to cancel an airstrike on Iran over the downing of a U.S. drone, and his meeting with Kim Jong Un in the DMZ between North Korea and South Korea. Bolton didn’t go on the short-notice North Korea trip, instead continuing to Mongolia as he had already planned.

“From hot spot to hot spot around the globe, Trump and Bolton simply saw things differently, making conflict between them inevitable,” he wrote. “Trump also reportedly disliked Bolton’s trademark mustache.”

“Yet focusing on the specific conflicts between Bolton and Trump misses the point. The problem is not that Trump doesn’t get along with his national security adviser; it’s that he doesn’t want one in the first place.”